first filter. This is payback. It is totally payback
Evolution. Humans used to have more fur than we do now, but with the changing in climate and where humans lived, being able to sweat to keep the body cool became more and more beneficial. It didn't work so well with a heavy fur coat though as that'd just keep the moisture trapped and wouldn't let it to evaporate to help chill out the body. Some fur stayed put though for protection of one sort or another.